Being Open Source code Proftpd is available primarily as
source code for local compilation. There are a number of
maintainers within the project who create the packaged builds
for the primary platforms and distributions. For most users the
packaged builds will prove to be sufficient and the least hassle
route to installing Proftpd. However to use the daemon to it's
fullest or to explore some of the more interesting features a
local custom build will be required.

Architecture

Proftpd was designed from the ground up to be both
extensible and as secure by design as possible. Security is
discussed in depth later in this document, however while there
are no known security holes it cannot be said of this or any
other piece of software that there are no problems waiting to
be found. The extensibility is provided by means of a modular
architecture which takes many lessons and features from the
Apache webserver project. Almost all the functionality has
been supplied by moving most functions into modules. This
includes features such as "ls" and the authentication
handling, this approach allows third party developers to
provide additional modules to latch onto these hooks to add or
extend the basics provided. Most of the more interesting
modules have to be compiled in as they are not part of the
standard builds. Unfortunately dynamically loadable modules
are not available within the 1.2.x code tree though
development and testing is planned for the 1.3.x development
branch.